In order to get the value of the given expression, let's convert it to an exponential form. Here's the pattern:
[tex]log_by=x\Leftrightarrow y=b^x[/tex]Let's convert the given expression in the problem using the pattern above.
[tex]log_4\text{ }x=3\Leftrightarrow x=4^3[/tex]So, let's solve 4³.
[tex]4^3=4\times4\times4=64[/tex]Therefore, the value of x is 64.
Answer: The solution set is {64}. Option A.